1. Field of the Invention
The disclosure relates generally to a fastening device, and more particularly to a fastening device for mounting a thermal module onto a heat generating electronic component.
2. Description of Related Art
It is widely acknowledged that heat is produced during operation of electronic components such as central processing units (CPUs) of computers. The heat produced by the CPUs must be quickly removed to protect the CPU. Typically, a thermal module is provided to remove heat from a CPU of a notebook computer. To maintain intimate contact with the CPU, a fastening device is generally required.
A conventional thermal module includes a thermal attachment block, a heat pipe, a fin assembly and a plurality of elastic members. The block has a bottom surface contacting a CPU mounted on a printed circuit board and a top surface defining a groove therein. The heat pipe includes an evaporator section received in the groove of the block, and a condenser section thermally contacted to the fin assembly. The elastic members are disposed at two opposite sides or four corners of the block. The elastic members and the block are firmly combined by soldering or riveting. An assembly hole is defined adjacent to a free end of each elastic member for mounting the thermal module to the printed circuit board. When the thermal module is mounted to the printed circuit board, the block is disposed on a top surface of the CPU. The assembly holes of the elastic members align with corresponding mounting holes of the printed circuit board. Fasteners extend through the assembly holes of the elastic members and engage with mounting holes of the printed circuit board, lowering the block. Thus, the thermal module is mounted to the printed circuit board with the block thermally contacting the electronic component.
However, the elastic members are firmly combined with the block by soldering or riveting, rendering the thermal module applicable for only printed circuit boards with appropriately positioned mounting holes. When positions of the mounting holes are changed due to changed requirements of layout of components on the printed circuit board, a newly designed block can be applied. In addition, soldering or riveting stress can deform junctures of the elastic members and the block, adversely affecting contact between the block and the heat generating electronic component, thereby reducing heat transfer efficiency therebetween.
What is needed, therefore, is an thermal module with improved fastening device which can overcome the limitations described.